Question

Which of the following is a rule regarding contour lines?

1. Contour lines can cross each other if the cliff is vertical.
2. Contour lines are always colored blue.
3. Contour lines never cross each other.
4. Contour lines always stop at the edge of a valley.

• A. iii only
• B. i, ii
• C. All
• D. i only

Answer 1

Answer:

A. iii only

• Since each line represents a specific elevation, crossing would imply a single point has two different heights. • Contour lines function as isolines—lines that connect points of equal value. • In topography, that value is elevation above sea level. • For two lines to cross, a single physical spot on the Earth's surface would need to exist at two different altitudes simultaneously, which is physically impossible in a standard three-dimensional landscape.